Molteni R A, Melmed M H, Sheldon R E, Jones M D, Meschia G
Am J Obstet Gynecol. 1980 Mar 1;136(5):609-20. doi: 10.1016/0002-9378(80)91012-1.
Sustained and vigorous fetal breathing activity was produced in a chronic fetal lamb preparation by infusion into the fetus of either NH4Cl or HCl. Over a 2 to 3 hour period, 20 to 25 mEq/kg were infused. All of the fetuses tolerated blood pH values of 6.7 to 6.8 and survived. The breathing activity began after the completion of the infusion, and consisted of regular 30 to 50 torr inspirations at a rate of 60 to 120 breaths/min. This activity was continuous for as much as 8 hours, and persisted with pauses and decreased amplitude for 24 to 36 hours. During fetal breathing, blood flow to the diaphragm and intercostal muscles increased approximately 12- and sixfold, respectively.
通过向慢性制备的胎羊胎儿输注氯化铵或盐酸，可产生持续且强烈的胎儿呼吸活动。在2至3小时内，以20至25毫当量/千克的剂量进行输注。所有胎儿均耐受6.7至6.8的血液pH值并存活下来。呼吸活动在输注完成后开始，由30至50托的规则吸气组成，频率为60至120次/分钟。这种活动持续长达8小时，并在有停顿且幅度减小的情况下持续24至36小时。在胎儿呼吸期间，流向膈肌和肋间肌的血流量分别增加了约12倍和6倍。
